The invention concerns a motor vehicle door, comprising a door inside part, a door outside part and a supporting panel which is connected in a tight-fitting manner to the door inside part. The door inside part and door outside part are conventional sheet-metal shells which also form the window frame and to which the hinges, the door lock and optionally a door stopper are fitted; the supporting panel bears the diverse assemblies, such as window guides and window openers, and recently also has been given the task of protecting the occupants during lateral and frontal collisions. The relevant regulations are becoming ever stricter. Because of them, there is an increase, on the one hand, in the safety requirements but, on the other hand, the production costs have to drop.
DE 198 09 750 A1 discloses a motor vehicle door in which a very stiff supporting panel is clamped between the two sheet-metal shells. Although said supporting panel provides very good protection against penetration during a lateral collision, its small degree of extension means that the deformation distances are too small for effective retardation. The clamping between the sheet-metal shells in the plane of the supporting panel does not permit any effective sealing between the outer space of the door, in which the window is guided, and the inner space, in which the electrics are accommodated. The two sheet-metal shells are bulky and complex punched parts, the precisely fitting joining together of which is difficult during assembly. A door constructed in this manner is still heavy and cannot be used for different vehicle variants (for example, coupe and convertible). But this is precisely what is desirable for reducing costs.
DE 197 44 810 A1 discloses a motor vehicle door in which a frame module can be lowered from above into a door box comprising two sheet-metal shells. The frame module has, below the window opening, a module carrier which forms a blocking layer and bears diverse assemblies. This achieves a limited modularity of the door because the door box only forms the basic door below the window, but does not achieve a noticeable reduction in weight or a further reduction in costs.
In the case of the door of the xe2x80x9cSMARTxe2x80x9d car known in practice, hinges, the lock, the guides of frameless windows, diverse assemblies and an,interior covering are fitted to an inner supporting framework consisting of light metal profiles. The outer skin is only pushed onto the supporting framework. Although this construction is light in weight, it cannot be satisfactory with regard to occupant protection for vehicles of normal dimensions. In addition, the outer skin can easily be removed from the outside, which is an invitation for thieves.
It is the object of the present invention to provide a door construction which considerably surpasses known constructions with regard to safety, protection of the occupants, weight and costs. The reduction in the costs requires modularization to the greatest possible extent, i.e. the basic elements of supporting panel, interior covering and outer skin have to be able to be combined with one another in different variants.
The foregoing object is achieved by providing a supporting panel consisting of a reinforced plastic is a solid structural part which satisfies all static and dynamic load situations, such as frontal collision, side collision, quasi-static door indentation, door depression and door over-compression. It also serves as a support for all of the door assemblies and the door covering. On account of the tight-fitting fastening, it also serves as a separation of wet zone and dry zone, with the window on the outer side of the supporting panel being situated in the wet zone. Given appropriate selection of material, the solid supporting panel may also serve as attack-proof armor-plating.
The connection of the edge of the supporting panel in its plane to a first and a second frame plate can be screwed or riveted and permits tolerance compensation, which facilitates the assembly and improves the fitting precision of the finished door. Since the frame plates are folded profiles, they can be deformed in the event of a collision and thus compensate for the small deformation distance of the stiff supporting panel. This effect is further increased by the first, parallel limb of the profile being connected to the edge of the supporting plate and its second limb being directed transversely to the surface of the door and being deformed in the case of a collision.
Since the door inside part is a shell consisting of plastic, stiffness matching the function is obtained even with a small wall thickness. The shell is of such a depth that the door inside part protrudes outward over the supporting panel and forms a connecting flange. In the interior of the shell, the supporting panel bears completely or at points against first fitting surfaces via the frame plates and bears directly against a second fitting surface and is fastened there in a tight-fitting manner in each case. The fastening takes place by means of screws or rivets which again also permit tolerance compensation. The solid supporting panel, which is connected in a tight-fitting manner to the door inside part consisting of plastic, also provides audibly better muffling of noises.
The door outside part is a skin which is fastened in a positive manner to the connecting flange. Said door outside part can consist of any desired material (steel, light metal or plastic) because it does not come into contact with the metallic frame. Thus, electrochemical reactions cannot occur. The positive connection is only accessible with the door open, i.e. security against theft is increased. With the door open, it can, however, easily be interchanged, which is an advantage in, the case of relatively light damage or for individuals wanting different colored doors. The relatively flat shape of the outer skin furthermore results in simple production and free selection of the material.
The first frame plate is preferably connected to hinges and the second frame plate is preferably connected to a door lock. Force is therefore introduced from the supporting panel directly to the hinges or to the lock without loading the door inside part.
In a development of the invention, a collision protection support is provided which is fastened by its ends to the first and second frame plates outside the supporting panel Since it is outside the supporting panel, it thus has a relatively large deformation distance even before the supporting panel comes into effect.
The profile of the first and second frame plates preferably has, at least in part, a third limb which is approximately parallel to the first limb and is outside the latter. This third limb not only stiffens the frame plate and enlarges its capacity for absorbing deformation energy; it is also to be intended that the collision protection support is fastened to it. The fastening to the frame plate again provides direct introduction of force into the lock and hinges with an interaction between the supporting panel and collision protection support being provided via the frame plate.
A further aspect of the invention comprises the first and second frame plates extending as far as the lower edge of the window opening, and a separate window frame being placed on the upper edge of the supporting panel and being fastened to the first limb and to third limb of the profile. This means, first of all, that the door can be used both with and without window frames (as a frameless window for Cabriolets). In this case, the resting on the supporting panel and the adjustable connection to the frame permits sufficiently stiff fastening and precise adjustment during assembly. The latter because the first and third limbs of the profile are parallel and at some distance from each other. This is a substantial step to complete modularity.
Within the context of the invention, the supporting panel itself can differ greatly in design. In a particularly suitable design, it comprises an inner wall and an outer wall consisting of fiber-reinforced plastic, which walls are connected to each other at least along the edge, and cavities being provided between the walls. They can also be connected in the meantime by inwardly directed ribs. This produces maximum stiffness at the lowest weight. The fastening elements then engage on the common edge. There is thus a solid separating wall between the wet zone and dry zone. No a damage is done if the supporting panel has an aperture which forms an inner edge and at which the walls are connected to each other. On the contrary: if the window opener motor is accommodated in this aperture and is connected in a tight-fitting manner to the inner edge, its electrics are situated in the dry zonexe2x80x94and, as a result, conventional plugs are sufficientxe2x80x94and its output is situated in the wet zone which also contains the window.
In an advantageous development of the invention, the supporting panel has integrated metallic inserts for fastening means Said inserts can be molded metal parts, in particular threaded bushings, and can accommodate the fastening means for the frame plates and also the fastening means for diverse, further assemblies, for example the window guides on the side facing the door outside part.
A further step toward producing full modularity comprises the door inside part having, on its surface facing the vehicle interior, inserts or openings for the attachment of insert parts or covering parts. Said parts can then be used as desired in various furnishing variants, colors or qualities. In the extreme case, the openings can be so large that the door inside part just forms a frame into which then an entire door interior covering complete with loudspeakers etc. can be inserted.
In a preferred development, the door inside part has, on its upper edge, a window seal and plug-in elements with which it is placed, vertically onto the supporting panel. The door inside part therefore extends as far as the window, is securely fastened and yet can easily be fitted.
In a development, the door inside part has a peripheral rubber seal which bears against the supporting panel. In the case of particularly exacting requirements or in complicated situations, this measure can improve the sealing of the dry zone and at the same time acts in a noise-isolating manner. There are exacting requirements, for example, if the cabling is pre-assembled on the inside of the door inside part and normal lines and plugs are used and are to last for a long time.
In a development of the invention, provision is made for the door outside part to have, on its three edges which are connected to the door inside part, inwardly folded zones with holes in which the positive fastening means engage through holes in the connecting flange. In this manner, the connection is not only inaccessible with the door closed, but is also invisible. If it is also to be invisible with the door open and is additionally to be protected from moisture, then a sealing lip can be provided on the connecting flange on the door inside part, said sealing lip overlapping the positive fastening means on that side of the door inside part which faces away from the door outside part. Finally, the door outside part can have a reinforcement and a window seal on its upper edge.